I was reading about F-35's version that can take of vertically and it's mentioned that they are using a patented technology by Rolls-Royce called Fanlift and Liftsystem which brings me the questions:
Do other countries have to be partnered with Rolls-Royce to develop such technology (exact one)?
What if Rolls-Royce doesn't want to partner with them?
Isn't this a way of saying: "Here is a way to kill you but you can not kill us back?"
I do not have deep knowledge of patents and how they operate, would be glad to be explained.